pgsql: Remove workarounds against repeat typedefs

Remove workarounds against repeat typedefs

This is allowed in C11, so we don't need the workarounds anymore.

Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/10d32190-f31b-40a5-b177-11db55597355@eisentraut.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1e3b5edb8eb236f16529ca8dae917996ad1f433e

Modified Files
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src/include/nodes/pathnodes.h     | 23 ++++-------------------
src/include/optimizer/optimizer.h | 13 +------------
2 files changed, 5 insertions(+), 31 deletions(-)